Scilex Holding Company announced complete enrollment in a Phase 2, randomized, double-blind, placebo-controlled, parallel group, multicenter study to evaluate the safety and efficacy of SP-103 (lidocaine topical system) 5.4% triple strength formulation for ZTlido®, in subjects with acute LBP. Scilex is developing SP-103 to be a triple-strength, non-aqueous lidocaine topical system for the treatment of acute LBP. Acute LBP can range in intensity from a dull, constant ache to a sudden, sharp sensation that leaves the person incapacitated.

It is estimated that approximately 65 million adults in the U.S., or 25% of adults in the U.S., suffer from acute LBP1 with a total potential global market opportunity of approximately $10.0 billion by 2026. More than 60% of U.S. opioid prescriptions are for the treatment of chronic low back pain (CLBP)2 despite the fact that opioids are associated with serious and potentially life-threatening side effects and have not demonstrated efficacy in the treatment of CLBP.3,4,5 Provisional data from CDC's National Center for Health Statistics indicate there were an estimated 107,622 drug overdose deaths in the United States during 2021, an increase of nearly 15% from the 93,655 deaths estimated in 2020.6 The new data show overdose deaths involving opioids increased from an estimated 70,029 in 2020 to 80,816 in 2021. There are currently no approved non-NSAID (non-steroidal anti-inflammatory drugs) pharmaceutical treatments specifically indicated for the treatment of acute LBP.

The market intend to address with SP-103, if approved, includes etiologies that are currently treated with non-procedural or non-surgical interventions, and where available treatments provide inadequate pain relief or result in unacceptable adverse effects. These treatments may include NSAIDs, antidepressants and opioids, as well as off-label lidocaine patches. The safe and effective treatment of acute LBP represents a high unmet need and creates a large market opportunity.

LBP is one of the most costly benign conditions in industrialized countries. Experts have estimated that approximately 80% of Americans will experience LBP during their lifetime. The annual prevalence of LBP is 15% to 45% with a point prevalence of approximately 30% in the United States.

Sixty percent of those who suffer from acute LBP recover in six weeks and up to 80-90% recover within 12 weeks7. However, the recovery of the remaining patients with LBP is less certain. LBP accounts for 19% of all workers' compensation claims in the United States.

Americans spent at least $135 billion in 2016 on treating low back and neck pain, which was the expenditure among 154 conditions. SP-103 builds on the learnings from ZTlido because both products share the same adhesive drug delivery formulation and manufacturing technology. If approved, believe that SP-103 could become the leading lidocaine topical product for acute LBP indications.

All current uses of topical lidocaine products for acute LBP are off label. SP-103 has three times the drug load of ZTlido (108 mg versus 36 mg) in the same adhesive system to potentially deliver threefold the level of the drug within a targeted area, still with the convenience of a single topical system. Additionally, SP-103 is designed to deliver a localized dose of lidocaine that is three times greater than any lidocaine topical product that are aware of either on the market or in development.

If approved, believe SP-103 may be able to address the limitations of prescription lidocaine patches in treating acute LBP by delivering a higher dose of lidocaine to the application site. As part of the lifecycle management, Scilex will also target localized musculoskeletal pain, acute and chronic pain conditions, and post operation pain management to focus on developing and commercializing non-opioid therapies for patients with acute and chronic pain. Scilex expects to get top line data in the third quarter of 2023.

The outcome of the Phase 2 study should enable planning of a subsequent Pivotal Phase 3 trial.